dash-determine-which-button-was-clicked.py

# Determine which input changed, or which button was clicked, using
# the latest functionality in dash-html-components (https://github.com/plotly/dash-html-components/pull/45)
import dash
from dash.dependencies import Input, Output
import dash_core_components as dcc
import dash_html_components as html
import datetime
import json

app = dash.Dash()

app.layout = html.Div([
    html.Button('Button 1', id='btn-1', n_clicks_timestamp='0'),
    html.Button('Button 2', id='btn-2', n_clicks_timestamp='0'),
    html.Button('Button 3', id='btn-3', n_clicks_timestamp='0'),
    html.Div(id='container')
])


@app.callback(Output('container', 'children'),
              [Input('btn-1', 'n_clicks_timestamp'),
               Input('btn-2', 'n_clicks_timestamp'),
               Input('btn-3', 'n_clicks_timestamp')])
def display(btn1, btn2, btn3):
    if int(btn1) > int(btn2) and int(btn1) > int(btn3):
        msg = 'Button 1 was most recently clicked'
    elif int(btn2) > int(btn1) and int(btn2) > int(btn3):
        msg = 'Button 2 was most recently clicked'
    elif int(btn3) > int(btn1) and int(btn3) > int(btn2):
        msg = 'Button 3 was most recently clicked'
    else:
        msg = 'None of the buttons have been clicked yet'
    return html.Div([
        html.Div('btn1: {}'.format(btn1)),
        html.Div('btn2: {}'.format(btn2)),
        html.Div('btn3: {}'.format(btn3)),
        html.Div(msg)
    ])

if __name__ == '__main__':
    app.run_server(debug=True)